1. Field of the Invention
The present invention relates to display systems. More specifically, the present invention relates to display systems for an audio spectrum.
While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications, and embodiments within the scope thereof and additional fields in which the present invention would be of significant utility.
2. Description of the Related Art
Spectrum analyzers sample time-varying signals and display the energy content in x - y format as a function of frequency. Typically, the power spectral density of signal is displayed as the ordinate versus frequency as the abscissa. This linear signal representation is suitable for general signal measurement, audio through microwave, where energy content versus frequency information is desired.
However, for audio signals additional manipulation of spectral information may be very useful. Human perception recognizes tonal relationships: pitch of tones, combinations of tones (chords, vocal vowels, etc.), and the variety of miscellaneous sounds in the environment. When audio signals are displayed on a spectrum analyzer, the power spectral density in the signal is represented in a linear fashion. One with a well trained eye might be able to identify certain patterns in a static signal or single frames of a dynamic signal, especially those involving large peaks and valleys. However, it is extremely difficult for the average viewer to recognize pitch and harmonic content in most audio signals, particularly dynamic signals. Pitch and harmonic content from the conventional display can be obtained only by identifying the specific frequencies, then performing tasks including looking up pitch tables and performing mathematic operations to establish intervals between the frequencies.
Pitch and harmonic content recognition capability could aid in speech training for the hearing impaired by providing good visual display of vocal sounds to be imitated by the trainee. This capability could also have application in voice recognition, synthetic speech, electronic music, graphic equalizers and general electronic entertainment.
Accordingly, there is a need in the art for a system and technique for displaying the power spectral density of audio signals to facilitate the recognition of pitch and harmonic content therein.